Equipment, Office Facilities, and Property (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Total equipment, office facilities, and property	$ 6,330	$ 5,550
Accumulated depreciation and amortization	(2,888)	(2,667)
Total equipment, office facilities, and property — net	3,442	2,883
Software [Member]
Property, Plant and Equipment [Line Items]
Total equipment, office facilities, and property	2,524	2,314
Buildings [Member]
Property, Plant and Equipment [Line Items]
Total equipment, office facilities, and property	1,640	1,444
Information technology equipment [Member]
Property, Plant and Equipment [Line Items]
Total equipment, office facilities, and property	679	509
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Total equipment, office facilities, and property	462	455
Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Total equipment, office facilities, and property	429	325
Land [Member]
Property, Plant and Equipment [Line Items]
Total equipment, office facilities, and property	208	208
Property, Plant and Equipment, Other Types [Member]
Property, Plant and Equipment [Line Items]
Total equipment, office facilities, and property	$ 388	$ 295